Metal corner trim, comprising a strip of light metal bent at a right angle along its longitudinal center-line, has been used for years to establish rigid, straight edges for wall corners in dry wall construction. More recently, the edge line formed by the intersection of the two bent sides of the beading material has been replaced with a rounded section intermediate the two flat sides that are positioned ninety degrees from one another. The rounded corner edging material has come to be known in the trade as "bullnose." After the surfaces of the flat metal side portions of the bullnose trimming strip are feathered into the dry wall surface with taping mud and texture, a pleasantly rounded corner edge is presented.
When cutting the length of a strip of bullnose that extends from floor to ceiling to size only straight right angle cuts are required. These cuts can be made with conventional sheet metal shears. However, when cutting to length a strip of bullnose that is to be used to edge the corner of a window casing, for example, the end of the strip of bullnose must be mitered in order to fit it properly with the mating end of a similarly mitered piece that is position at right angles to the first piece. Since most angles in a building are right angles the mitered edge is usually cut at 45.degree. to the length of the strip.
The use of traditional sheet metal shears to cut angles on flat material has not presented a significant problem, but as the form of corner trim transitions from flat surfaces with a beaded corner to a curved surface that forms the rounded portion of the bullnose, cutting with ordinary sheet metal shears presents critical problems. First, drawing a satisfactory angular line across a first flat surface, then across the curved metal surface of the bullnose and then across the second flat surface is difficult in the working environment. Second, following the drawn line with sufficient accuracy so as not to create a mitered edge that will not fit snugly with a mating edge is very difficult with conventional sheet metal shears. The predictable result of such an effort is to leave the mitered edge rough, bent and disposed to produce holes between or overlaps with its mating piece, which is also cut with the same impression. Cutting the mitered edge without trying to follow a line renders the same, if not worse, results.
Accordingly, it is the primary object of the present invention to provide a pair of shears for cutting mitered edges on bullnose that will follow a designated angular course across the width of the bullnose in order to execute a well defined mitered edge that is even and straight and will appropriately abut an adjoining piece of angularly disposed and mitered bullnose.
A second object of the invention is to provide a pair of shears for cutting mitered edges on bullnose that does not require a drawn line to follow.
A sill further object of the invention is to provide a pair a bullnose shears that are easy to use and accurate in their execution.
Other and still further objects, features and advantages of the invention will become apparent upon a reading of the following description of a preferred form of the invention, taken in conjunction with drawings that accompany the description.